Method and system for providing offset to computed evapotranspiration values

ABSTRACT

A system for providing irrigation control is provided. The system includes a processor configured to calculate an offset to an evapotranspiration (ET) value and an irrigation system configured to receive the offset from the processor and provide appropriate irrigation adjustment based on the offset. The offset is calculated based on the ET value and the ET value has been previously provided to the irrigation system.

CROSS-REFERENCES TO RELATED APPLICATION(S)

The present application claims the benefit of priority under 35 U.S.C.§119 from (1) U.S. Provisional Patent Application Ser. No. 60/515,905,entitled “METHOD FOR PROVIDING OFFSET TO COMPUTED EVAPOTRANSPIRATIONVALUES”, filed on Oct. 29, 2003, (2) U.S. Provisional Patent ApplicationSer. No. 60/515,932, entitled “METHOD FOR CONTROLLING IRRIGATION USINGCOMPUTED EVAPOTRANSPIRATION VALUES”, filed on Oct. 29, 2003, and (3)U.S. Provisional Patent Application Ser. No. 60/515,628, entitled“METHOD FOR CONTROLLING AN IRRIGATION SCHEDULING ENGINE USING COMPUTEDEVAPOTRANSPIRATION VALUES”, filed on Oct. 29, 2003, the disclosures ofwhich are hereby incorporated by reference in their entirety for allpurposes.

BACKGROUND OF THE INVENTION

The present invention generally relates to irrigation control and, morespecifically, to methods and systems for providing offset to computedevapotranspiration (ET) values in a remote manner.

Typically, irrigation control information is manually input by an userto an irrigation system in order to allow the irrigation system toprovide an appropriate amount of irrigation. Such irrigation controlinformation is generally based on measurements obtained by the user fromother equipment and/or data collected by a weather station. Theirrigation system, in turn, provides an appropriate amount of irrigationbased on the input information.

The foregoing irrigation arrangement has a number of shortcomings. Forexample, the user has to first obtain the requisite irrigation controlinformation and then manually input such information into the irrigationsystem. Furthermore, such information does not necessarily accuratelyreflect the local weather conditions that are applicable to the areascovered by the irrigation system. This is because the irrigation controlinformation may be generated based on data collected by a distant ornon-local weather station that is located some distance away from theareas covered by the irrigation system. The weather station may belocated in an area where the weather conditions vary quite significantlyfrom those of the areas covered by the irrigation system. As a result,the irrigation control information (which is based on data collectedfrom the distant weather station) may cause the irrigation system toprovide irrigation that is substantially different from what is requiredfor the areas covered by the irrigation system.

Furthermore, due to inaccuracies in measuring weather conditions,irrigation control information often needs to be updated. For example,in some conventional irrigation systems, a new ET value is calculatedsolely based on the latest weather conditions. The new ET value,however, does not take into account irrigation already performed basedon any past erroneous ET value. As a result, the resulting irrigationbased on the new ET value does not initially accurately reflect the trueweather conditions. It is only after a certain adjustment period thatthe resulting irrigation based on the new ET value conforms to the trueweather conditions.

Hence, it would be desirable to provide a system that is capable ofproviding accurate irrigation in a more efficient manner.

SUMMARY OF THE INVENTION

In one embodiment, a system for providing irrigation control isprovided. The system includes a processor configured to calculate anoffset to an evapotranspiration (ET) value, and an irrigation systemconfigured to receive the offset from the processor and provideappropriate irrigation adjustment based on the offset, wherein theoffset is calculated based on the ET value and the ET value has beenpreviously provided to the irrigation system.

In another embodiment, a system for providing irrigation controlincludes a processor configured to calculate an offset to anevapotranspiration (ET) value, the processor further configured tocreate or alter an irrigation program based on the offset, and anirrigation system configured to receive the irrigation program from theprocessor and provide appropriate irrigation adjustment based on theirrigation program, wherein the offset is calculated based on the ETvalue and the ET value was used to create or alter a prior irrigationprogram previously provided to the irrigation system.

In yet another embodiment, a system for providing irrigation controlincludes a number of non-local data sources for providing data, aprocessor configured to receive data from one or more of the non-localdata sources and calculate an offset to an evapotranspiration (ET) valuefor an area that is non-local with respect to the non-local datasources, the processor further configured to create or alter anirrigation program based on the offset, wherein the offset is calculatedbased on the ET value, and an irrigation system located in the area andconfigured to receive the irrigation program from the processor andprovide appropriate irrigation adjustment for the area using theirrigation program.

In a further embodiment, a system for providing irrigation controlincludes a number of non-local data sources for providing data, aprocessor configured to receive data from one or more of the non-localdata sources and calculate an offset to an evapotranspiration (ET) valuefor an area that is non-local with respect to the non-local datasources, the processor further configured to create one or morecomponents constituting an irrigation program based on the offset,wherein the offset is calculated based on the ET value, and anirrigation system located in the area and configured to receive the oneor more components from the processor.

In yet a further embodiment, a system for providing irrigation controlincludes a number of non-local data sources for providing data, aprocessor configured to receive data from one or more of the non-localdata sources and calculate an offset to an evapotranspiration (ET) valuefor an area that is non-local with respect to the non-local datasources, wherein the offset is calculated based on the ET value, and anirrigation system located in the area and configured to receive theoffset from the processor, create or alter an irrigation program basedon the offset and provide appropriate irrigation adjustment for the areausing the irrigation program.

In one aspect of the present invention, a method for providingirrigation control is provided. The method includes: calculating anoffset to an evapotranspiration (ET) value, forwarding the offset to anirrigation system, and directing the irrigation system to provideappropriate irrigation adjustment based on the offset, wherein theoffset is calculated based on the ET value and the ET value has beenpreviously provided to the irrigation system.

In another aspect of the present invention, a method for providingirrigation control includes: calculating an offset to anevapotranspiration (ET) value, creating or altering an irrigationprogram based on the offset, forwarding the irrigation program to anirrigation system, and directing the irrigation system to provideappropriate irrigation adjustment based on the irrigation program,wherein the offset is calculated based on the ET value and the ET valuewas used to create or alter a prior irrigation program previouslyprovided to the irrigation system.

In yet another aspect of the present invention, a method for providingirrigation control includes: receiving data from one or more non-localdata sources, using the data received from the one or more non-localdata sources to calculate an offset to an evapotranspiration (ET) valuefor an area that is non-local with respect to the non-local datasources, wherein the offset is calculated based on the ET value,creating or altering an irrigation program based on the offset, andreceiving the irrigation program at an irrigation system, and directingthe irrigation system to provide appropriate irrigation adjustment forthe area using the irrigation program.

In a further aspect of the present invention, a method for providingirrigation control includes: receiving data from one or more non-localdata sources, using the data received from the one or more non-localdata sources to calculate an offset to an evapotranspiration (ET) valuefor an area that is non-local with respect to the one or more non-localdata sources, wherein the offset is calculated based on the ET value,creating one or more components constituting an irrigation program basedon the offset, and forwarding the one or more components to anirrigation system located in the area.

In yet a further aspect of the present invention, a method for providingirrigation control includes: receiving data from one or more non-localdata sources, using the data received from the one or more non-localdata sources to calculate an offset to an evapotranspiration (ET) valuefor an area that is non-local with respect to the one or more non-localdata sources, wherein the offset is calculated based on the ET value,forwarding the offset to an irrigation system located in the area, anddirecting the irrigation system to create or alter an irrigation programbased on the offset and provide appropriate irrigation adjustment forthe area using the irrigation program.

Reference to the remaining portions of the specification, including thedrawings and claims, will realize other features and advantages of thepresent invention. Further features and advantages of the presentinvention, as well as the structure and operation of various embodimentsof the present invention, are described in detail below with respect toaccompanying drawings, like reference numbers indicate identical orfunctionally similar elements.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects, advantages and novel features of the present invention willbecome apparent from the following description of the inventionpresented in conjunction with the accompanying drawings:

FIG. 1 is a simplified schematic block diagram illustrating oneembodiment of the present invention; and

FIG. 2 is a simplified schematic block diagram illustrating oneembodiment of an irrigation system according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention in the form of one or more embodiments will now bedescribed. As shown in FIG. 1, one embodiment of the present inventionis a system 100 that includes a number of non-local data sources 102a-c, a processor 104 and an irrigation system 106. The processor 104 isconfigured to receive data from one or more of the non-local datasources 102 a-c, use such data to compute an ET value and then transferthe computed ET value to the irrigation system 106. The irrigationsystem 106 is configured to receive the computed ET value from theprocessor 104 and provide irrigation or perform other irrigationfunctions accordingly.

Each data source 102 provides information that can be utilized togenerate irrigation control information including, for example, an ETvalue. The ET value is calculated based on a number of parametersincluding, for example, relative humidity, soil temperature, airtemperature, wind speed and solar radiation. The number of parametersmay vary depending on the methodology that is used to calculate the ETvalue. The data sources 102 a-c collectively provide information onthese parameters. Each data source 102 may provide informationcorresponding to one or more parameters. The information is then used tocompute the ET value, as will be further described below. Data from thenon-local data sources 102 a-c is used because the area in which theirrigation system 106 is located does not have sufficient measuringapparatus or resources to obtain local information that is needed todetermine the ET value in that area.

The data sources 102 a-c are non-local in the sense that they are notlocated in the same general area as the irrigation system 106. Forexample, one data source is the National Weather Service which providesgeneral weather information across the United States; other data sourcesinclude databases or data feeds from various universities and governmentagencies. It should be understood that the meaning of the term“non-local” is not strictly defined by physical distance; “non-local”may also refer to an area that is subject to generally different weatherconditions. For example, two areas may be physically close to oneanother; however, they may be non-local with respect to each otherbecause they have generally different weather conditions attributed todifferent geographical topologies and different topographies. Asmentioned before, the data sources 102 a-c collectively provide datathat relate to the various parameters that are used to compute the ETvalue for the area(s) covered by the irrigation system 106. For example,data collected from the data sources 102 a-c include surfaceobservations, upper air observations, sea surface temperatures andcurrent global initialization 4D (4-dimensional) grids, etc.

Data from the data sources 102 a-c are transmitted to the processor 104.It should be noted that data from the data sources 102 a-c can betransmitted to the processor 104 in a number of ways including, forexample, via a computer network such as the Internet. Based on thedisclosure and teachings provided herein, a person of ordinary skill inthe art will know of other ways and/or methods to transmit the data fromthe data sources 102 a-c to the processor 104 in accordance with thepresent invention.

The processor 104, in turn, processes the data to calculate the desiredET value for each particular area covered by the irrigation system 106.First, the processor 104 calculates the requisite weather parameters in4D space.

The weather parameters in 4D space are calculated as follows. Thegridded terrain elevation, vegetation and land use are horizontallyinterpolated onto each mesoscale domain. Input fields such as soiltypes, vegetation fraction, and deep soil temperature, are populatedfrom historical data.

Then, the 4D gridded meteorological analyses on pressure levels areinput and those analyses are interpolated from global grids to eachmesoscale domain. The foregoing steps perform the pressure-level andsurface analyses. Two-dimensional interpolation is performed on theselevels to ensure a completely populated grid.

Next, the global initialization on each mesoscale grid is adjusted byincorporating observation data from the data sources 102 a-c. Differenttypes of observation data are used including, for example, traditionaldirect observations of temperature, humidity, wind from surface andupper air data as well as remote sensed data, such as, radar andsatellite imagery. The three-dimensional and four-dimensionalvariational techniques both integrate and perform quality control on thedata, eliminating questionable data to improve the global initializationgrids.

The initial boundary conditions are then calculated and formatted forinput to a numerical weather model. It will be appreciated that a numberof different numerical weather models can be used depending on eachparticular application. Based on the disclosure and teachings providedherein, a person of ordinary skill in the art will know how to selectthe appropriate numerical weather model in accordance with the presentinvention. For example, one process converts pressure level data to an“S” coordinate system under bounded conditions in 4D space (x, y, z andtime). The integrated mean divergence or noise conditions that theinitial analyses may contain are then removed to create a stable basestate for the numerical weather model.

Using the numerical weather model, and the appropriate physics options,the requisite weather parameters in 4D space are then calculated. Thisis a fully bounded 4D grid in both space and time with known startingand ending conditions.

Calculation of the weather parameters can be performed by the processor104 using a number of modeling applications (not shown) that arepublicly available. These modeling applications can be modified toperform the functions as described above. One such modeling applicationis known as the PSU/NCAR mesoscale model (known as MM5). The MM5 is alimited-area, nonhydrostatic, terrain-following sigma-coordinate modeldesigned to simulate or predict mesoscale atmospheric circulation.Another such modeling application is the WRF (Weather Research andForecasting) model created by UCAR (University Corporation forAtmospheric Research). Based on the disclosure and teachings providedherein, a person of ordinary skill in the art will know how to selectand modify the various available modeling applications for use inaccordance with the present invention.

The calculated weather parameters outputted from the numerical weathermodel are then used to calculate the ET value for a target location in2D space. Corresponding weather parameters needed for calculating the ETvalue for the target location are extracted at specific x, y, z & timelocations.

The ET value at the target location is then calculated and a 2D griddedsurface for the 24 hour period is created. It should be understood thatthe ET value may be calculated based on one of a number of differentformulas. Based on the disclosure and teachings provided herein, aperson of ordinary skill in the art will appreciate how to select theappropriate formula depending on each particular situation.

Finally, any artifacts, edge effects and anomalies created by mesoscalegrid boundaries conditions and/or errors are eliminated.

The processor 104 then transfers the computed ET value to the irrigationsystem 106. Upon receiving the computed ET value, the irrigation system106 can then provide the proper irrigation or perform other irrigationfunctions in an automated manner.

The processor 104 is typically located at some distance away from theirrigation system 106. The transfer of the computed ET value from theprocessor 104 to the irrigation system 106 can be done in a number ofways. For example, the computed ET value can be transmitted to theirrigation system 106 via wired or wireless communications. Based on thedisclosure and teachings provided herein, a person of ordinary skill inthe art will know of other ways and/or methods to transfer the computedET value from the processor 104 to the irrigation system 106.

Furthermore, in one embodiment, the processor 104 first encrypts ormathematically alters the computed ET value before transferring it tothe irrigation system 106. The irrigation system 106 is equipped withthe corresponding decryption algorithm to decrypt or restore thecomputed ET value.

In an alternative embodiment, after the processor 104 derives theweather parameters, such weather parameters are transferred to theirrigation system 106. Using the transferred weather parameters, theirrigation system 106 then computes the appropriate ET value.Optionally, the processor 104 can encrypt the weather parameters beforetransferring them to the irrigation system 106 and the irrigation system106 is equipped with the corresponding decryption algorithm to decryptor restore such data.

In one embodiment, as shown in FIG. 2, the irrigation system 106 furtherincludes a scheduling engine 108. The scheduling engine 108 furtherincludes an irrigation program 110 that is designed to control variouscomponents of the irrigation system 106 to automatically provide properirrigation or perform other irrigation functions. The scheduling engine108 may use the received or derived computed ET value to either createone or more new irrigation programs or, alternatively, alter one or moreexisting irrigation programs.

In an alternative embodiment, after the processor 104 computes the ETvalue as described above, the processor 104 uses the computed ET valueto create or alter an irrigation program 110 suitable for the irrigationsystem 106. The irrigation program 110 is then transferred or uploadedto the irrigation system 106. Subsequently, the scheduling engine 108uses the irrigation program 110 to provide the proper irrigation orperform other irrigation functions.

Alternatively, the processor 104 uses the computed ET value to createinformation that can be used by the scheduling engine 108 to update oralter the irrigation program 110. Such information is then forwarded bythe processor 104 to the scheduling engine 108 so as to allow thescheduling engine 108 to update or alter the irrigation program 110.

In another alternative embodiment, after the irrigation program 110 iscreated or altered, the processor 104 breaks down the irrigation program110 into one or more component values. Such component values are thentransferred from the processor 104 to the scheduling engine 108. Thescheduling engine 108 uses such component values to derive orre-constitute the irrigation program 110. The irrigation program 110 isthen used by the scheduling engine 108 to provide the proper irrigationor perform other irrigation functions. The component values of theirrigation program 110 may be individually transmitted to the schedulingengine 108 at different times.

Optionally, the irrigation program 110 or component values thereof aremathematically altered or encrypted before they are transferred to theirrigation system 106 by the processor 104. The irrigation system 106 isequipped with the corresponding decryption algorithm to decrypt orrestore the irrigation program 110 or component values thereof.

In one embodiment, the irrigation program 110 has a number of discretestates respectively representing various stages of irrigation to beprovided by the irrigation system 106. The processor 104 executes theirrigation program 110 and, upon arriving at a particular discretestate, the processor 104 transfers information relating to thatparticular discrete state to the scheduling engine 108. The schedulingengine 108, in response, provides the proper irrigation or performsother irrigation functions.

Optionally, the information relating to the discrete states can bemathematically altered or encrypted before it is transferred to thescheduling engine 108. The scheduling engine 108 is equipped with thecorresponding decryption algorithm to decrypt or restore suchinformation.

In addition, in some situations, the ET value is computed based onerroneous information. In one embodiment, the processor 104 isconfigured to re-calculate a new, correct ET value using the latest,accurate information. Moreover, using the new ET value and the old ETvalue, the processor 104 is further configured to calculate an offset.The offset is similar to a delta function that represents a correctionto the old ET value. The processor 104 then transfers the offset to theirrigation system 106. The irrigation system 106, in turn, updates theold ET value with the offset and provides the appropriate irrigation orperforms other irrigation functions via, for example, the schedulingengine 108 and/or the irrigation program 110. Since the old ET value istaken into consideration when the offset is calculated, past erroneousirrigation is corrected by the irrigation system 106 when the offset isused by the scheduling engine 108 and/or irrigation program 110 toprovide the proper irrigation.

Optionally, the offset can be mathematically altered or encrypted beforeit is transferred to the irrigation system 106.

In an alternative embodiment described above where the processor 104creates or alters an irrigation program 110 based on the computed ETvalue, the processor 104 can further utilize the offset to create a newirrigation program or alter an existing irrigation program. The new oraltered irrigation program can then be forwarded to the irrigationsystem 106.

In an exemplary implementation, the present invention is implementedusing software in the form of control logic, in either an integrated ora modular manner. The control logic may reside on a computer-readablemedium executable by the processor 104 or a computer. Alternatively,hardware or a combination of software and hardware can also be used toimplement the present invention. Based on the disclosure and teachingsprovided herein, a person of ordinary skill in the art will know ofother ways and/or methods to implement the present invention.

It is understood that the examples and embodiments described herein arefor illustrative purposes only and that various modifications or changesin light thereof will be suggested to persons skilled in the art and areto be included within the spirit and purview of this application andscope of the appended claims. All publications, patents, and patentapplications cited herein are hereby incorporated by reference for allpurposes in their entirety.

1. A system for providing irrigation control, comprising: a processorconfigured to calculate an offset to an evapotranspiration (ET) value;and an irrigation system configured to receive the offset from theprocessor and provide appropriate irrigation adjustment based on theoffset; wherein the offset is calculated based on the ET value and theET value has been previously provided to the irrigation system.
 2. Thesystem of claim 1 wherein the irrigation system is further configured toupdate an irrigation program based on the offset and provide appropriateirrigation adjustment based on the updated irrigation program.
 3. Thesystem of claim 1 wherein the processor is further configured to encryptthe offset; and wherein the irrigation system is further configured todecrypt the offset received from the processor.
 4. A system forproviding irrigation control, comprising: a processor configured tocalculate an offset to an evapotranspiration (ET) value, the processorfurther configured to create or alter an irrigation program based on theoffset; and an irrigation system configured to receive the irrigationprogram from the processor and provide appropriate irrigation adjustmentbased on the irrigation program; wherein the offset is calculated basedon the ET value and the ET value was used to create or alter a priorirrigation program previously provided to the irrigation system.
 5. Thesystem of claim 4 wherein the processor is further configured to encryptthe irrigation program; and wherein the irrigation system is furtherconfigured to decrypt the irrigation program received from theprocessor.
 6. A system for providing irrigation control, comprising: aplurality of non-local data sources for providing data; a processorconfigured to receive data from one or more of the plurality ofnon-local data sources and calculate an offset to an evapotranspiration(ET) value for an irrigation area that is non-local with respect to theplurality of non-local data sources, the processor further configured tocreate or alter an irrigation program based on the offset, wherein theoffset is calculated based on the ET value; and an irrigation systemconfigured to receive the irrigation program from the processor andprovide appropriate irrigation adjustment for the irrigation area usingthe irrigation program.
 7. The system of claim 6 wherein the processoris further configured to encrypt the irrigation program for transmissionto the irrigation system; and wherein the irrigation system is furtherconfigured to decrypt the irrigation program received from theprocessor.
 8. A system for providing irrigation control, comprising: aplurality of non-local data sources for providing data; a processorconfigured to receive data from one or more of the plurality ofnon-local data sources and calculate an offset to an evapotranspiration(ET) value for an irrigation area that is non-local with respect to theplurality of non-local data sources, the processor further configured tocreate one or more components constituting an irrigation program basedon the offset, wherein the offset is calculated based on the ET value;and an irrigation system configured to receive the one or morecomponents from the processor.
 9. The system of claim 8 wherein theirrigation system is further configured to use the one or morecomponents received from the processor to derive the irrigation programand provide appropriate irrigation adjustment based on the irrigationprogram.
 10. The system of claim 8 wherein the processor is furtherconfigured to encrypt the one or more components for transmission to theirrigation system; and wherein the irrigation system is furtherconfigured to decrypt the one or more components received from theprocessor.
 11. A system for providing irrigation control, comprising: aplurality of non-local data sources for providing data; a processorconfigured to receive data from one or more of the plurality ofnon-local data sources and calculate an offset to an evapotranspiration(ET) value for an irrigation area that is non-local with respect to theplurality of non-local data sources, wherein the offset is calculatedbased on the ET value; and an irrigation system configured to receivethe offset from the processor, create or alter an irrigation programbased on the offset and provide appropriate irrigation adjustment forthe irrigation area using the irrigation program.
 12. The system ofclaim 11 wherein the processor is further configured to encrypt theoffset for transmission to the irrigation system; and wherein theirrigation system is further configured to decrypt the offset receivedfrom the processor.
 13. A method for providing irrigation control,comprising: calculating an offset to an evapotranspiration (ET) value;forwarding the offset to an irrigation system; and directing theirrigation system to provide appropriate irrigation adjustment based onthe offset; wherein the offset is calculated based on the ET value andthe ET value has been previously provided to the irrigation system. 14.The method of claim 13 further comprising: updating an irrigationprogram associated with the irrigation system based on the offset; andproviding appropriate irrigation adjustment based on the updatedirrigation program.
 15. The method of claim 13 further comprising:encrypting the offset; and decrypting the offset at the irrigationsystem.
 16. A method for providing irrigation control, comprising:calculating an offset to an evapotranspiration (ET) value; creating oraltering an irrigation program based on the offset; forwarding theirrigation program to an irrigation system; and directing the irrigationsystem to provide appropriate irrigation adjustment based on theirrigation program; wherein the offset is calculated based on the ETvalue and the ET value was used to create or alter a prior irrigationprogram previously provided to the irrigation system.
 17. The method ofclaim 16 further comprising: encrypting the irrigation program; anddecrypting the irrigation program at the irrigation system.
 18. A methodfor providing irrigation control, comprising: receiving data from one ormore non-local data sources; using the data received from the one ormore non-local data sources to calculate an offset to anevapotranspiration (ET) value for an irrigation area that is non-localwith respect to the one or more non-local data sources, wherein theoffset is calculated based on the ET value; creating or altering anirrigation program based on the offset; and receiving the irrigationprogram at an irrigation system; directing the irrigation system toprovide appropriate irrigation adjustment for the irrigation area usingthe irrigation program.
 19. The method of claim 18 further comprising:encrypting the irrigation program for transmission to the irrigationsystem; and decrypting the irrigation program at the irrigation system.20. A method for providing irrigation control, comprising: receivingdata from one or more non-local data sources; using the data receivedfrom the one or more non-local data sources to calculate an offset to anevapotranspiration (ET) value for an irrigation area that is non-localwith respect to the one or more non-local data sources, wherein theoffset is calculated based on the ET value; creating one or morecomponents constituting an irrigation program based on the offset; andforwarding the one or more components to an irrigation system.
 21. Themethod of claim 20 further comprising: directing the irrigation systemto use the one or more components to derive the irrigation program andprovide appropriate irrigation adjustment for the irrigation area basedon the irrigation program.
 22. The method of claim 20 furthercomprising: encrypting the one or more components for transmission tothe irrigation system; and decrypting the one or more components at theirrigation system.
 23. A method for providing irrigation control,comprising: receiving data from one or more non-local data sources;using the data received from the one or more non-local data sources tocalculate an offset to an evapotranspiration (ET) value for anirrigation area that is non-local with respect to the one or morenon-local data sources, wherein the offset is calculated based on the ETvalue; forwarding the offset to an irrigation system; and directing theirrigation system to create or alter an irrigation program based on theoffset and provide appropriate irrigation adjustment for the irrigationarea using the irrigation program.
 24. The method of claim 23 furthercomprising: encrypting the offset for transmission to the irrigationsystem; and directing the irrigation system to decrypt the offset.